Conventional diagnosis of skin cancer etc. has been made by pathological analysis, e.g., seeing the color of the skin, touching the skin by hand and/or taking a living tissue as a sample therefor. Observation by taking a living tissue sample, however, creates a painful burden to the patient, and can cause metastasis thereof if it is virulent cancer. Thus, it is not desirable to take a living tissue sample.
As a solution, a noninvasive test method has heretofore been proposed, wherein the color of the skin surface at respective positions is split so that a light of a wavelength specific to a predicted pathological change is detected through a plurality of filters, displaying the reflection intensity thereof as a two-dimensional image. An apparatus for measuring and displaying such spectroscopic images of colors are disclosed in Japanese Un-examined Patent Publication No. 2000-356552, for example.
The conventional measuring methods and apparatuses, however, have problems that there are many errors in detecting a pathological change since an image is obtained by choosing a wavelength characteristic of a specific color in accordance with an intended purpose, and then filtering the same; and that the measuring apparatuses become too complex since they use a plurality of filters.